I purchased a used QSC 850 and it is my first pre-amp/power amp rig. On the output section of the power amp the option is only for Speakons and banana plugs. One of the channels has a speakon to quarter inch adapter plugged into it. This came with the amp so I have no idea where it came from. I suppose I can plug my cab into this via a quarter inch cable. I know this seems like a real stupid question but I am totally ignorant about power amps ect. Please help an old bass idiot out.